Wheel cylinder adjuster

ABSTRACT

A wheel cylinder adjuster includes a body, a push rod, a resilient member and a positioning member. The push rod extends through the body and the resilient member is mounted to the push rod and located in the body. The push rod has a positioning part connected thereto and the positioning part contacts one end of the resilient member. The push rod has a connector and an activating disc respectively connected to two ends thereof, the connector has a holding rod extending therethrough. The positioning member is connected to the push rod so that the left-sided wheel cylinder and the right-sided wheel cylinder can be adjusted by using the single wheel cylinder adjuster.

BACKGROUND OF THE INVENTION

1. Fields of the Invention

The present invention relates to a wheel cylinder adjuster for adjustingthe right-sided wheel cylinder and the left-sided wheel cylinder, andmore particularly, to a wheel cylinder adjuster without using a threadedrod.

2. Descriptions of Related Art

The wheel cylinder of a vehicle becomes protruding outward along withthe wearing of the lining plates of the brake system. When replacing thelining plates, the wheel cylinders have to be moved back to theiroriginal positions by rotating the valve of the wheel cylinders andpushing the wheel cylinders to the original positions. The conventionalwheel cylinder adjuster 1 is disclosed in FIG. 1 and generally comprisesa threaded rod 10 which has one end connected with a holding rod 11, andthe other end of the threaded rod 10 has an activating disc 12 connectedthereto. A nut 13 and a positioning stop plate 14 are respectivelymounted to the threaded rod 10. The activating disc 12 contacts againstthe valve of the cylinder 2, and the positioning stop plate 14 contactsagainst the clamping seat 21. When the threaded rod 10 is rotated byoperating the holding rod 11, the valve 20 is pushed back to itsoriginal position. However, after the valve 20 is pushed back to itsoriginal position by rotating the threaded rod 13 to rotate theactivating disc 12, the activating disc 12 has to be moved backward byrotating the threaded rod 10 in opposite direction. It takes a lot oftime to continuously rotate the threaded rod 10. Besides, each of theleft wheel and the right wheel has a cylinder, so that the users have toprepare two threaded rods 10, one of which has left-handed threads, andthe other has right-handed threads so as to respectively adjust theleft-sided wheel cylinder and the right-sided wheel cylinder. This isinconvenient for the users.

The present invention intends to provide a wheel cylinder adjuster thatdoes not have the threaded rod and can be used for both of theleft-sided wheel cylinder and the right-sided wheel cylinder toeliminate the shortcomings mentioned above.

SUMMARY OF THE INVENTION

The present invention relates to a wheel cylinder adjuster and comprisesa body having a passage defined axially therethrough and the passagedefines an opening in the first end of the body. A push rod extendsthrough the passage of the body and has a polygonal positioningprotrusion extending from the first end thereof. A positioning ball isconnected to one side of the positioning protrusion. A connector isconnected to the second end of the push rod and has a through holedefined transversely therethrough. A holding rod extends through thethrough hole. A positioning part is connected to the push rod. Aresilient member is mounted to the push rod and has one end thereofcontacting the positioning part on the push rod. A positioning member isconnected to the push rod and has a tubular portion extending therefrom.An axial hole is defined in the positioning member. The push rod extendsthrough the axial hole. The positioning member has a flange.

Preferably, the passage defines another opening in the second end of thebody. Female threads are defined in the inner periphery of the secondend of the body. The tubular portion of the positioning member has malethreads which are threadedly engaged with female threads of the secondend of the body.

Preferably, the push rod has a recess defined in the second end thereof.A first pin hole is defined through the wall of the second end of thepush rod and communicates with the recess. The connector has anextension extending from one end thereof. The extension is inserted intothe recess of the push rod and has a second pin hole which is locatedcorresponding to the first pin hole of the push rod. A pin extendsthrough the first and second pin holes.

Preferably, the push rod has a positioning hole defined transverselytherethrough. The positioning part on the push rod is a collar which hasa third pin hole. Another pin extends through the third pin hole and thepositioning hole.

Preferably, the body has a positioning stop plate mounted thereto whichhas an aperture.

Preferably, an activating disc is connected to the positioningprotrusion of the push rod and has a polygonal insert hole in which thepositioning protrusion is inserted. The activating disc has at least twostuds on one side thereof.

The advantage of the present invention is that the left-sided wheelcylinder and the right-sided wheel cylinder can be adjusted by using thesingle wheel cylinder adjuster, and no threaded rod is needed.

The present invention will become more obvious from the followingdescription when taken in connection with the accompanying drawingswhich show, for purposes of illustration only, a preferred embodiment inaccordance with the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates the use of the conventional wheel cylinder adjuster;

FIG. 2 is an exploded view of the wheel cylinder adjuster of the presentinvention;

FIG. 3 is a perspective view to show the wheel cylinder adjuster of thepresent invention;

FIG. 4 is a cross sectional view of the wheel cylinder adjuster of thepresent invention;

FIG. 5 illustrates the use of the wheel cylinder adjuster of the presentinvention;

FIG. 6 is a cross sectional view to show that the push rod of the wheelcylinder adjuster of the present invention pushes the valve, and

FIG. 7 is a cross sectional view to show that the push rod of the wheelcylinder adjuster of the present invention is moved backward.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 2 to 4, the wheel cylinder adjuster of the presentinvention comprises a body 3 having a passage 30 defined axiallytherethrough. The passage 30 defining an opening 32 in the first end ofthe body 3, and the passage 30 also defines another opening in thesecond end of the body 3. Female threads 31 are defined in the innerperiphery of the second end of the body 3.

A push rod 4 extends through the passage 30 of the body 3 and has apolygonal positioning protrusion 40 extending from the first endthereof. A positioning ball 41 is connected to one side of thepositioning protrusion 40. A recess 42 defined in the second end of thepush rod 4. A first pin hole 43 is defined through the wall of thesecond end of the push rod 4 and communicates with the recess 42. Thepush rod 4 has a positioning hole 45 defined transversely therethrough.

A connector 5 is connected to the second end of the push rod 4 and has athrough hole 52 defined transversely therethrough. A holding rod 53extends through the through hole 52. The connector 5 has an extension 50extending from one end thereof. The extension 50 is inserted into therecess 42 of the push rod 4 and has a second pin hole 51 which islocated corresponding to the first pin hole 43 of the push rod 4. A pin44 extends through the first and second pin holes 43, 51.

A positioning part is connected to the push rod 4, in this embodiment,the positioning part on the push rod 4 is a collar 6 which has a thirdpin hole 60. Another pin 61 extends through the third pin hole 60 andthe positioning hole 45.

A resilient member 46 is mounted to the push rod 4 and has one endthereof contacting the collar 6 on the push rod 4. The body 3 furtherhas a positioning stop plate 7 mounted thereto which has an aperture 70.A positioning member 8 is connected to the push rod 4 and has a tubularportion 80 extending therefrom. The tubular portion 80 of thepositioning member 8 has male threads 81 which are threadedly engagedwith female threads 31 of the second end of the body 3. An axial hole 82is defined in the positioning member 8, and the push rod 4 extendsthrough the axial hole 82. The positioning member 8 has a flange 83extending radially from one end thereof. The flange 83 positions thepositioning stop plate 7 between the body 3 and the positioning member8.

An activating disc 9 is connected to the positioning protrusion 40 ofthe push rod 4 and has a polygonal insert hole 90 in which thepositioning protrusion is inserted. The activating disc 9 has at leasttwo studs 91 on one side thereof.

When in assembly, the collar 6 is mounted to the push rod 4, and thethird pin hole 60 of the collar 6 is located corresponding to thepositioning hole 45 of the push rod 4. The pin 61 extends through thethird pin hole 60 of the collar 6 and the positioning hole 45 of thepush rod 4 so as to connect the collar 6 to the push rod 4. Theresilient member 46 is mounted to the push rod 4 which is then extendsthrough the passage 30 of the body 3 so that the second end of the pushrod 4 protrudes from the opening 32 of the body 3. The resilient member46 and the collar 6 are located in the passage 30 of the body 3. Theresilient member 46 is biased between the inner end of the passage 30and one side of the collar 6. The extension 50 of the connector 5 isthen inserted into the recess 42 of the push rod 4 to make the secondpin hole 51 be located corresponding to the first pin hole 43. The pin44 extends through the first pin hole 43 and the second pin hole 51 toconnect the connector 5 to the second end of the push rod 4. The holdingrod 53 extends through the through hole 52 of the connector 5, and thepositioning member 8 extends through the aperture 70 of the positioningstop plate 7 to contact the flange 83 against the positioning stop plate7. The positioning member 8 is then mounted to the push rod 4, and themale threads 81 of the tubular portion 80 of the positioning member 8are threadedly engaged with female threads 31 of the second end of thebody 3, so that the positioning member 8 and the positioning stop plate7 are fixed to the body 3. The activating disc 9 is then connected tothe positioning protrusion 40 of the push rod 4. The positioning ball 41on the positioning protrusion 40 contacts an inside of the insert hole90 of the activating disc 9 to connect the activating disc 9 to thepositioning protrusion 40.

When adjusting the wheel cylinder 2, as shown in FIGS. 4 to 7, the wheelcylinder adjuster is connected to the wheel cylinder 2, and thepositioning stop plate 7 is connected to the clamping seat 21. Theresilient member 46 pushes the collar 6 to move the push rod 4, so thatthe activating disc 9 on the push rod 4 contacts against the valve 20 ofthe wheel cylinder 2. The studs 91 of the activating disc 9 are engagedwith the notches 22 of the valve 20. The holding rod 53 is rotated torotate the push rod 4 so that the activating disc 9 rotates the valve 20inwardly until the valve 20 is moved to its original position. After thevalve 20 is moved back to its original position, to remove theactivating disc 9, as shown in FIG. 7, the user simply holds the holdingrod 53 to pull the push rod 4 outward, the collar 6 on the push rod 4compresses the resilient member 46 so that the activating disc 9 on thepush rod 4 is removed from the wheel cylinder 2. When the activatingdisc 9 is separated from the valve 20, the body 3 can be detached fromthe wheel cylinder 2. When releasing the holding rod 53, the resilientmember 46 bounces back to push the push rod 4 back to its originalposition. Therefore, the wheel cylinder 2 is adjusted by using thesingle wheel cylinder adjuster of the present invention. The singlewheel cylinder adjuster of the present invention can adjust theleft-sided wheel cylinder and the right-sided wheel cylinder, and nothreaded rod is needed.

While we have shown and described the embodiment in accordance with thepresent invention, it should be clear to those skilled in the art thatfurther embodiments may be made without departing from the scope of thepresent invention.

What is claimed is:
 1. A wheel cylinder adjuster comprising: a bodyhaving a passage defined axially therethrough, the passage defining anopening in a first end of the body; a push rod extending through thepassage of the body and having a polygonal positioning protrusionextending from a first end thereof, a positioning ball being connectedto a side of the positioning protrusion, a connector connected to asecond end of the push rod and having a through hole definedtransversely therethrough, a holding rod extending through the throughhole, a positioning part connected to the push rod; a resilient membermounted to the push rod and having one end thereof contacting thepositioning part on the push rod, and a positioning member connected tothe push rod and having a tubular portion extending therefrom, an axialhole defined in the positioning member, the push rod extending throughthe axial hole, the positioning member having a flange.
 2. The wheelcylinder adjuster as claimed in claim 1, wherein the passage definesanother opening in a second end of the body, female threads are definedin an inner periphery of the second end of the body, the tubular portionof the positioning member has male threads which are threadedly engagedwith female threads of the second end of the body.
 3. The wheel cylinderadjuster as claimed in claim 1, wherein the push rod has a recessdefined in a second end thereof, a first pin hole defined through a wallof the second end of the push rod and communicates with the recess, theconnector has an extension extending from one end thereof, the extensionis inserted into the recess of the push rod and has a second pin holewhich is located corresponding to the first pin hole of the push rod, apin extends through the first and second pin holes.
 4. The wheelcylinder adjuster as claimed in claim 1, wherein the push rod has apositioning hole defined transversely therethrough, the positioning parton the push rod is a collar which has a third pin hole, another pinextends through the third pin hole and the positioning hole.
 5. Thewheel cylinder adjuster as claimed in claim 1, wherein the body has apositioning stop plate mounted thereto which has an aperture.
 6. Thewheel cylinder adjuster as claimed in claim 1, wherein an activatingdisc is connected to the positioning protrusion of the push rod and hasa polygonal insert hole in which the positioning protrusion is inserted,the activating disc has at least two studs on one side thereof.